Evaluation of Discrete Address Beacon System (DABS) EMC
The FAA is currently developing the Discrete Address Beacon System (DABS) as an evolutionary upgrading of the Air Traffic Control Radar Beacon System (ATCRBS). Questions have been raised regarding the Electromagnetic Compatibility (EMC) of ATCRBS and DABS because of their common channel usage. The committee on Science and Technology, U.S. House of Representatives, requested that the National Telecommunications and Information Administration (NTIA) review DABS as a radio telecommunication system giving particular attention to potential interference problems.
The EMC of DABS with operational and firmly planned systems in the 960-1215 MHz band was investigated. This was accomplished by evaluating FAA theoretical calculation, measurement, and simulation results, and performing an independent analysis through theoretical calculations and computer simulations.
It was concluded that replacing FAA ATCRBS ground sensors with DABS sensors, operating according to FAA specified scenarios, will not reduce the performance of the remaining ATCRBS sensors or the DABS sensors. The compatibility of DABS with TACAN/DME, MSL/DME, and BCAS is operationally and technically manageable. The compatibility of the ATCRBS IFF Mark XII System (AIMS) and DABS is being addressed in a joint FAA and DoD EMC study.